X-ray pulsar

A neutron star centered in a disk of hot plasma drawn
from its red companion star. Accreting material from the disk, the
neutron star spins faster and faster emitting powerful particle beams
and pulses of X-rays as it rotates 400 times a second. Credit: W.
Feimer (Allied Signal), GSFC, NASA

An X-ray binary in which the compact object
is a neutron star with a powerful magnetic
field that gives rise to regular X-ray pulses.
These pulses are thought to be caused by the magnetic field channeling the
accreting gas on to the poles of the compact star, producing localized hot
spots that move in and out of view as the star spins. Hercules
X-1 is an example. Anomalous
X-ray pulsars (AXPs) make up an unusual subcategory.